Leading Question: What is Mioskowski's Reagent?
Charles Mioskowski’s reagent is tetraethyl ammonium trichloride. It is an organic salt that is an efficient source of chlorine. It can be prepared by bubbling chrlorine through tetraethylammonium chloride solution in dichloromethane. It can be stored for a long time period at room temperature with no decrease in reactivity.
The key facet of this reagent that makes it so useful is its ability to chlorinate a wide range of organic species under mild conditions. These species include alkynes, alkenes, aldehydes, ketones, esters, acetals, and arenes. Alkenes and alkynes get dichlorinated (E stereoisomer selectivity) upon treatment. Ketones are selectively monochlorinated at the the alpha position. Alpha, beta-unsaturated ketones are converted into the corresponding alpha, beta-unsaturated alpha-chloroketones. Esters fail to react with Mioskowski’s reagent. Aromatic compounds(activated with an electron donating group) were chlorinated at the para position.
Tetraethyl ammonium trichloride is a stable cyrstalline solid that is easy to handle, which a short reaxtion time. Both of these factors make it an efficient chlorinating agent that produces no byproducts, as is the case when iodoperchloride salts are used.